Electric light



A ELDISE QNE BIwhrimLights.

No. 221,227. Patented May 4,1880.

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UNITED STATES PATENT OFFICE.

THOMAS A. EDISON, OF MENLO PARK, NEW JERSEY.

ELECTRIC LIGHT.

SPECIFICATION forming part of Letters Patent No. 227,227, dated May 4,1880.

Application filed February 10, 1879.

To all whom it may concern Be it known that I, THOMAS A. EDISON, ofMenlo Park, in the State of New Jersey, have invented an Improvement inElectric Lights, (Case No. 171,) of which the following is aspecification.

The object of this invention is to economically apply electricity tolighting and to insure uniformity of action in the dili'erent lamps.

The invention consists, first, in an improved incandescent lamp andregulator; second, in an automatic switch connected with the regulatorof the lamp to connect it with the line; third, in grouping severallamps in such a manner that their combined resistance shall be the sameas one lamp.

Figure 1 represents the lamp and the circuitconnections. 1, 2, 3, 4, 5,and 6 are coils ofwire preferably flattened wire formed of an alloy ofplatinum and iridium, or metallic nickel. There are six of these coils,(see Fig. -l-,) each of which is slipped over a pencil of pipe-clay,which may be provided at the top end with a head, as shown in Fig. 1.

These pipe-clay pencils are secured to pipeclay disks as a), resting inthe split metal cup y y. Goil No.2 has its lower end connected to thebinding-screw m of the cup y. The top end of the spiral 2 connects tothe spiral 3, the bottom of 3 to at, the top of 4 to 5, the bottom ot'5to 6, the top of 6 to 1. The bottom of 1 connects to the screw it of thebrass cup y.

(1 and p are electric conductors between the divided cup y y and thedivided baser and r, and at the same time serve as supports to theburner.

The wire of the coils as it comes from the winding-machine is stretchedto open the coils, and then dipped in a thick milky solution of zirconoxide and clay and then passed through a hydrogen flame. This causes avery slight coating to adhere to the wire.

The coils are pressed together and placed on the fire-clay pencils, andthe coils are confined between the heads of the fire-clay pencils andthe clay blocks a as, into holes in which blocks the ends of suchfire-clay pencils are pressed. The coils forming the spirals are thus incontact, or nearly so, but they do not connect electrically; hence thecurrent passes through the whole length of the wire. The expansion ofthe pencil of clay, or clay and zircon, is about equal to that of themetal coils; hence their condition is not materially altered by theheat.

The spirals are of such a size that they nearly touch each other. Hencethe light and heat are confined within the circular range of spirals,and aid in intensifying the light and heat of the electric candle, andthe radiation is mostly from the outside portions of the coils.

The pipe'clay disks ;1 3 serve both for holding the pencils andpreventing the lower ends of the spirals from cooling by having theirheat conducted downward by the metal supports q p.

2 1 is a glass globe or shade set over the burner, and made air-tight,or nearly so. Air can only pass through the orifice 71/, as shown by thearrow. v

The regulation by the electric current, and the consequent temperatureof the burner, is obtained by the expansion of the air contained in theglass shade 24.

, 10 and 11 are flexible chambers, similar to those used in ananeroid-barometer. The expansion of the air by the heat of the burnercauses these chambers to bulge outwardly and gives a downward motion tothe lever 12, which is secured to the chamber 11 .at 13.

15 is a long rod tipped with platinum. 14 is a contact-point, and thelever 17 usually rests against it; but when the heat of the burner hasreached its maximum point it has expanded the air sufficiently to causethe lever 12 and point 15 to separate the lever 17 from 14 and divertthe electric current from the lamp.

WVhen the lamp is in operation the current passes from wire 50 to point23, which is in contact with the spring 22, (the regulatorscrew 19keeping 22 and 23 in contact;) thence the current passes to binding-postand lever 17 thence to contact-point 14:, to 1', through the spirals tor,- thence by wire 30 to the other binding-post, and out by wire 51.

It, now, the temperature of the spirals becomes too great, the lever 12and point 15 are thrown downward, and the lever 17 separated fromP01111314, thus throwing the lamp entirely out of circuit and placing incircuit a resistance, R equal to it, the object of the resistance beingto prevent an excessive spark at the contact-points.

I remark that if the current is accurately circulated for the lamp theresistance of B may be much greater than the lamp, and such resistancemay even be in the form of several spirals placed between the spirals 1,2, 3, 4, 5, and 6.

When the lever 17 is in contact with the point 15 and lever 12, thecurrent passes by wire 50 to 23; thence through 22 to bindingpost, to17; thence through 15 and 12 to the coil R by wire 54; thence by wire 30to the binding-post, and out by wire 51.

The block 16, upon which the lever 17 and point 14 are attached, ismovable, and it is adjusted by means of the screw 19, that passesthrough the stationary nut 18. By moving this block 16 toward the lampthe circuit is broken to the candle and closed through 15 and 17, and inso doing the circuit from 50 is broken between the spring 22 andscrew-point 23. The reverse movement causes the lamp to be automaticallyconnected to the circuit when the regulator-screw is turned downward tolight the lamp.

The parts can be so arranged that the lamp will be disconnected when itis giving a light equal to about two-candle power.

In Fig. 2 are shown switches 41 and 42, whereby the lamps may bedisconnected from the circuit after being turned down, as shown in myprevious application, No. 169.

It is obvious that any of the various forms of thermal circuit-regulatoralready described in my previous patents may be combined with the burnerherein shown.

, In Fig. 3 is shown the before-described lamp with mercury substitutedfor the aneroid-chambers.

In Fig. 2 I have shown a single lamp, L, having, say, one thousand ohmsresistance, placed in one branch, and in another branch I have shownfour electric candles or burners, L L L U, in one lamp. The burner beingin close proximity and arranged in two branch circuits, the resistanceof each branch being two thousand ohms, the two branches will jointlyoffer a resistance of one thousand ohms, the same as the resistance ofthe one lamp L.

By this arrangement various numbers of lamps may be placed in branchcircuits be tween the same main conductors and the resistance be equalin each branch.

In my application for a patent No. 162 I have shown a glass shade inwhich the air is confined, and acts by its expansion upon a diaphragm tooperate the electric-circuit regulator, and in my application No. 162 Ihave represented the confined air as acting upon a column of mercury,and in my application for a patent No. 166 I have shown the lamp ascomposed of a flattened coil of wire, and in my application No. 169 Ihave shown a rheostat or resistance that is thrown into the circuit whenthe lamp is extinguished.

I claim as my invention- 1. The combination, with the electric lamp andits transparent shade, of the aneroidchambers 10 and 11 andelectric-circuit regulator, substantially as set forth.

2. In an electric lamp, the combination, with a core of pipe-clay orequivalent nonconducting material and a base of similar material, towhich the core is connected, a helix of platiua or equivalent materialsurrounding the core and the wires of the electric circuit connectedthereto, substantially as set forth.

3. In an electric lamp, a circular range of parallel helices connectedalternately at top and bottom, and at the endsto the electricconductors, substantially as set forth.

4. The combination, in an electric lamp, of. the divided base i 0",standards 1; q, divided cup y y, and a circular range of parallelhelices and circuit-connections, substantially as set forth.

5. The combination, with the electric lamp and thermalcircuit-regulator, of the movable block 16, levers l2 and 17,contact-points 1 1 15, adjusting-screw 19, rheostat It, andcircuit-connections, substantially as and for the purposes set forth.

6. The automatic switch 22 23, in combination with the screw 19, block16, circuit-counections, thermal circuit-regulator, and electric lamp,substantially as set forth.

7. The arrangement of i'our electric lamps in a divided branch circuitbetween two main conductors, substantially as and for the purposes setforth.

Signed by me this 6th day of February, A. D. 1879.

THOMAS A. EDISON.

Witnesses:

STOCKTON L. GRIFFIN, WM. GARMAN.

